Snag?

[chucketn]

I'm reading " Textbook of Advanced Machine Work", a Google digitized book by Robert H. Smith copywrited in 1919. I keep running into the term Snag, used in the "'schedule of operations". This is the description of the process of making a part that lists the steps, tools and time required for each step. Each schedule starts with Snag. Anyone have a definition of Snag?
The term apears in the first two projects covered in the book, both involve turning operations on a cast iron bar between centers.

Chuck in E. TN

 

[jpeter]

Does that refer to cleaning up a casting like removing the gates and flash?

 

[joeby]

Yep, snagging is the process of cleaning up the castings by grinding of the excess, as jpeter stated. You can sometimes see some rough looking evidence on finished parts.

Interesting comparison between castings made, say 100 years ago, compared with ones made recently. Back then, people were much more concerned with the finished products appearance, it seems.

Kevin

 

[Blogwitch]

If the term does mean cleaning up, we have a special word for it in the UK, to fettle, I am fettling, it is fettled, and the person doing it is called a fettler.

It is a term still used today in certain areas of the country. Mainly in the pottery and metal casting businesses.

Just another bit of useless information.


Bogs

 

[tel]

It's fettling here as well. Snags are found in river beds and on BBQ's.

 

[Peter.]

Snagging is a universally-used term in the UK building trade. It's the process of picking-out minor (or sometimes major) faults in 'finished' work prior to handing over as completed. A contractor would obtain a 'snag-list', which they would work through effecting remedial works until the client was satisfied.

 

[jpeter]

Fettle, never before heard the term. Here in the US snagging also refers to a method of fishing. Basically the word is used to describe catching most anything by blindly hooking it, i.e., the extension cord got snagged in the chair leg. But I concour with whoever said "cleaning up a casting by grinding" is snagging.

 

[chucketn]

I have heard the use of snag in fishing and boating as a snag in the river that could catch your boat. Never heard/saw it used in machining until I found it in the referenced book from 1909. Also found it after posting in a second "Google" book from the same era. I would agree that it refers to cleaning a casting. Amazing that neither book had a glossary of terms nor was the term "Snag" defined anywhere in the book. Also could not find a definition that applied for machining or metal casting online.Thanks for the input folks!

 

[bearcar1]

Well that usage of the word snag is a new one on me as well. The art or practice of removing sprue remains or parting flash on a cast part has always been referred to as fettling and most likely remain that way for me. A compilation of items that need to be addressed and/or corrected during an ongoing project is referred to as a 'punch list'. You say tomato and I say tomatoe .... now if I could just decode some of the other obscure dialectual meanings that get bantered about sometimes.

on ya'
:big:

BC1
Jim

 

[shred]

You'll see "Snag grinding" mentioned in old machining texts. Basically it meant cleaning up the flash and other junk on a raw casting so it could be passed on to the machinists. A couple places define "fettling" as "removing the fettle", which was the term for the casting sand or mold material. It appears the two terms have now pretty much merged into one.

Amusingly I found a job description on a career web site:

"SNAG GRINDER"
Job Description and Jobs
DOT: 705.684-074

Cleans and rough finishes surfaces of casting, using powered grinding wheel mounted on counterbalanced frame: Positions casting under grinding wheel manually or using crane or hoist.

Grabs grinder handles and pulls wheel down against casting to remove projections, such as gates, fins, and parting lines, from surface. Repositions casting to grind other areas. May change position of belts on motor and pulleys to increase revolutions per minute when grinding wheel wears down. May remove cracks in surfaces of ingots, billets, and forgings, using grinder. May grind castings, using stationary grinder and be designated Stand Grinder (foundry).

 

[Tin Falcon]

You guys got me curios so I did a quick Google " definition snag" I somewhat expected definitions having nothing to do with this discussion. Well of course some did not like a snag on a pair of stockings. but his definition came up on the several sites I checked

2 : a rough sharp or jagged projecting part

while this is usualy asociated with a cut off tree limb .a stump or a part of a tree at or near the surface of a river or lake, this is certainly a current definition that apples to castings.
there is always something to learn here whether about engines , machining or the English language/American language.
Tin

 

[rickharris]

As an electronics engineer I always referred to final setting up as Fettling - Perhaps I got it from my Engineer Father.:

Some definitions:
Definitions of fettle on the Web:

* remove mold marks or sand from (a casting)
* a state of fitness and good health; "in fine fettle"
wordnetweb.princeton.edu/perl/webwn

* A state of proper physical condition; kilter or trim; One's mental state; spirits; Sand used to line a furnace; A person's mood or state, often assuming the worst; a seam line left by the meeting of mold pieces; To sort out, to fix; To line the hearth of a furnace with sand prior to pouring ...
en.wiktionary.org/wiki/fettle

* British term meaning the process of removing all runners and risers and cleaning off adhering sand from the casting. Also refers to the removal of slag from the inside of the cupola and in Britain to repair the bed of an open hearth.
www.sfsa.org/sfsa/glossary/deftrmff.php

* fettling: Making repairs to rail track, especially concerned with maintaining the drainage of the ballast, and the proper cant of the rail track and rails.
wapedia.mobi/en/Glossary_of_rail_terminology

* fettling - The removal, in the unfired state of excess body left in the shaping of pottery-ware at such places as seams and edges.

Snag is defined here http://www.iienet2.org/Details.aspx?id=645 as:
SNAG GRINDING. The nonprecision removal of unwanted material, such as sprues and gates in foundry operations by means of a grinding operation.

 

[tel]

Well, I'm glad we got all that sorted, I still prefer my snags tho'!!

 

[Maryak]

When you've had one too many at the Barby the snag is to decide how to remove the snags...............

Tongs ???

Fingers ???

Fork ???

Angle Grinder ???

Don't you just luv the English Language. ;D

Best Regards
Bob

 

[black85vette]

Don't you just luv the English Language. ;D

Scary part is that I recently read that China was soon to be the country with the largest English speaking population in the world!!

Wonder what snag means over there?